package net.zoneland.zrdp.common.utils;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import net.zoneland.zrdp.common.core.text.Convert;
import org.springframework.web.util.UriUtils;

/**
 * 客户端工具类
 *
 * @author zonevue
 */
public class ServletUtils
{

    private static final Logger LOGGER = LoggerFactory.getLogger(ServletUtils.class);

    private ServletUtils() {
        throw new IllegalStateException("Utility class");
    }
    /**
     * 获取String参数
     */
    public static String getParameter(final String name) {
        return getRequest().getParameter(name);
    }


    /**
     * 获取String参数
     */
    public static String getParameter(final String name, final String defaultValue) {
        return Convert.toStr(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获取Integer参数
     */
    public static Integer getParameterToInt(final String name) {
        return Convert.toInt(getRequest().getParameter(name));
    }

    /**
     * 获取Integer参数
     */
    public static Integer getParameterToInt(final String name, final Integer defaultValue) {
        return Convert.toInt(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获取Boolean参数
     */
    public static Boolean getParameterToBool(final String name) {
        return Convert.toBool(getRequest().getParameter(name));
    }

    /**
     * 获取Boolean参数
     */
    public static Boolean getParameterToBool(final String name, final Boolean defaultValue) {
        return Convert.toBool(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获得所有请求参数
     *
     * @param request 请求对象{@link ServletRequest}
     * @return Map
     */
    public static Map<String, String[]> getParams(final ServletRequest request) {
        final Map<String, String[]> map = request.getParameterMap();
        return Collections.unmodifiableMap(map);
    }

    /**
     * 获得所有请求参数
     *
     * @param request 请求对象{@link ServletRequest}
     * @return Map
     */
    public static Map<String, String> getParamMap(final ServletRequest request)
    {
        final Map<String, String> params = new HashMap<>();
        for (Map.Entry<String, String[]> entry : getParams(request).entrySet()) {
            params.put(entry.getKey(), StringUtils.join(entry.getValue(), ","));
        }
        return params;
    }

    /**
     * 获取request
     */
    public static HttpServletRequest getRequest() {
        return getRequestAttributes().getRequest();
    }

    /**
     * 获取response
     */
    public static HttpServletResponse getResponse() {
        return getRequestAttributes().getResponse();
    }

    /**
     * 获取session
     */
    public static HttpSession getSession() {
        return getRequest().getSession();
    }

    public static ServletRequestAttributes getRequestAttributes()
    {
        final RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
        if (attributes == null) {
            throw new NullPointerException("RequestAttributes null");
        }
        return (ServletRequestAttributes) attributes;
    }

    /**
     * 将字符串渲染到客户端
     *
     * @param response 渲染对象
     * @param string 待渲染的字符串
     */
    public static void renderString(final HttpServletResponse response, final String string)
    {
        try {
            response.setStatus(200);
            response.setContentType("application/json");
            response.setCharacterEncoding("utf-8");
            response.getWriter().print(string);
        } catch (final IOException e) {
            LOGGER.error("response write error:{}", string, e);
        }
    }

    /**
     * 是否是Ajax异步请求
     *
     * @param request HttpServletRequest
     */
    public static boolean isAjaxRequest(final HttpServletRequest request) {
        final String accept = request.getHeader("accept");
        if (accept != null && accept.contains("application/json")) {
            return true;
        }

        final String xRequestedWith = request.getHeader("X-Requested-With");
        if (xRequestedWith != null && xRequestedWith.contains("XMLHttpRequest")) {
            return true;
        }

        final String uri = request.getRequestURI();
        if (StringUtilPlus.inStringIgnoreCase(uri, ".json", ".xml")) {
            return true;
        }

        final String ajax = request.getParameter("__ajax");
        return StringUtilPlus.inStringIgnoreCase(ajax, "json", "xml");
    }

    /**
     * 内容编码
     *
     * @param str 内容
     * @return 编码后的内容
     */
    public static String urlEncode(final String str) {
        return UriUtils.encode(str, StandardCharsets.UTF_8);
    }

    /**
     * 内容解码
     *
     * @param str 内容
     * @return 解码后的内容
     */
    public static String urlDecode(final String str) {
        return UriUtils.decode(str, StandardCharsets.UTF_8);
    }

}
